1. Field of the Invention
The present invention relates-to an audio tape cassette. More particularly, the present invention relates to an audio tape cassette in which a magnetic tape has good runnability and does not suffer from edge damage, and which can reduce wow, flutter and modulation noise.
2. Description of the Related Art
An audio tape cassette generally comprises a cassette shell, a pair of hubs which is rotatively positioned in the cassette shell, a magnetic tape which is wound around the hubs, guiding parts which are positioned at suitable positions in the cassette shell and guide the magnetic tape in a running direction, and a felt pad which is positioned between the hubs and contacts a back of the magnetic tape and presses the magnetic tape to a magnetic head.
To improve runnability of the .magnetic tape in the cassette shell, various measures which improve the of friction between a magnetic layer of the magnetic tape and the magnetic head, the surface properties of the magnetic layer and/or hardness of the magnetic tape, or the accuracy and/or the material of the cassette shell and the guiding parts have been proposed.
However, since these measures for improving the runnability of the magnetic tape take only a part of the tape transportation into consideration, none of them has satisfactorily improved the runnability of the magnetic tape while reducing the wow, flutter and modulation noise effectively. In addition, an edge of the magnetic tape is broken or elongated to cause edge damage.